Question

18 The formula of the phosphate of an element
is RPO4, then the formulae of its hydroxide a
sulphide, respectively, are and
(a) R(OH)3 and R3S
(b) R(OH)2 and RS;
(c) R(OH)2 and R3S2
(d) R(OH)3 and RS3 it is of chemistry​

Answer 1

Answer:

The charge on PO4 ion is -3, so since the formula is RPO4 the charge of R ion must be +3

Charge on S ion = -2

Charge on OH = -1

So the formulae are:

R(OH)3 and R2S3

Answer 2

Answer:

$\bigstar\fcolorbox{blue}{green}{answer}\bigstar$

Explanation:

To solve this kind of questions, we need to know the oxidation states of different ions.

So we consider the oxidation state of the ion ' R' to be x

And we should be knowing that the oxidation state of a phospate ion is 3-.

The compound is made up of 2 ions basically:

$R ^ x and PO^ {3-} _{4}$

Now arrange these numbers and variables to form an equation

$\rightarrow x + (- 3) = 0$

$\fcolorbox{red}{green}{x = 3}$

Therefore the oxidation state of ion ' R' is 3+

The formula of hydroxide of R will be:

Cross multiply the valencies.

$\red{R = 3}$

$\red{OH = 1}$

$R(OH)_{3}$

$R = 3$

The formula of the sulfide of R will be as follows:

$R = 3$

$S = 2$

$R_{2} S_{3}$